1. Field of the Invention
The present invention relates to a post-cure inflator for inflating and cooling a cured tire by filling a high-pressure air into the cured tire and, more particularly, to separable upper and lower rims for holding the bead section of the cured tire and an upper and lower rim replacement apparatus.
2. Description of the Related Art
As a prior post-cure inflator, there has been in wide use a turnover-type post-cure inflator having two sets of upper and lower rims for holding a tire per cavity of a tire curing press, and designed to operate for tire expansion and cooling for at least one cycle time of the tire curing press and to turn over these upper and lower rims. Referring to FIG. 6, the upper and lower rims for holding a tire in such a post-cure inflator will be explained. An upper rim 11 and a lower rim 12 are separable disc-shaped rims and are made in a stepped form with their outer diameters 11a and 12a protruding to the size of bead diameter in order to hold the bead section B of the tire T, thus fixing and holding the bead section B of the tire T. Subsequently, the high-pressure air is filled in the tire, which therefore will be inflated by means of a pump not illustrated. Then the tire is turned over together with the upper and lower rims, being held in this state for a period of time over the one-cycle time of the tire curing press for self-cooling at a room temperature. When tires of different bead diameters are to be handled, therefore, it is necessary to replace the upper and lower rims with those having an outer diameter fit to the bead diameter, for the purpose of holding the tire while keeping its airtightness. It has been a general practice, therefore, to mount the upper and lower rims by bolts to the upper and lower rim supports so that these rims can be manually replaced.
The above-described post-cure inflator, however, has the following disadvantage that especially when the upper rim is to be mounted, a worker tightens bolts, looking at them from below, while holding a heavy upper rim up as high as the upper rim support above the post-cure inflator. This type of work requires several workers and moreover when a particularly large tire is handled in a limited, unstable footing, a large and heavy rim is required, resulting in lower work efficiency. Furthermore, since the lower rim of the post-cure inflator, after replacement, is mounted in a position which is as high as a worker's breast, raising a heavy lower rim to the level is a very hard work.